Aron's Records
1150 N. Highland Ave.
Los Angeles, CA 90038
Very close to Amoeba worth checking out for that reason alone. I've found a few items here before but not a great amount.

Dark Realm Records
8210 Firestone Blvd.
Downey, CA 90241
(562)923-2599
South LA county, close to Long Beach. Small store, lots of shirts, patches etc., mostly CDs, small amount of vinyls. Prices are average to high. You can listen to used CDs before you buy them here which is a plus sometimes.

I doubt you will find anything better than Amoeba. They have a great selection of well priced LPs. I noticed many NWN releases are stocked there often. I dont know about LPs but you can sample many of the CDs before you buy.

There are some killer shirt shops right up the street on Hollywood Blvd between Wilcox and Highland just walking distance from Amoeba. Many rare, import and bootleg tees to be found Definitly worth checking out.